Output When We Write Null = Null in Where Clause

In this blog we see the output of following query.

Query 1: Select * from sysobjects where null is null

Output

It return the total number of records of sysobjects.

NULL
Query 2: Select * from sysobjects where null = null

Output

It return 0 records of sysobjects.

Query 3: Select * from sysobjects where isnull(null,'')=''

Output

It returns the total number of records of sysobjects. The output of query1 and query3 is same.

output
I hope this is useful.